Drill or auger



(No Model.)

G. H. SELLERS. T DRILL 0R AUGER. No. 443,297.

Patented Dec. 23, 1890. I

.L V////// F //M ,l'oiriZ'l whomliit 11mg concerns-4 N STATES,

mar ries (.lEORGE' n. .snttnnspor .RIDLEY PARK, PENNSYLVANIA.

* onlLL ou AUGER.

sPEciflqaTIoi l'ifo -ming part of Letters lPatent No. 443,297, datedDecember 23,1 90. 1 1 Application filed June 28,1890. Serial No.357,027. (No model.) v I Be 'it known that I, GEORGE-H-.'i"SEIJLERS, of

Ridley'Park, Delaware county, state of Pennsylvania, have invented a newanduseful-Imtion, however, 'in its broader sense alsov in-.

provement in Drills and Angers, of which-the following is a true andexactdescrikption, reference being had to the accompanying drawings,which-*form apart of this specification.

,Myprcsent invention especially relates to an improved twistdrill oranger formed by a rolling or forging, process. The said invencludes atwisted or spirally-fluted drill having a central core with flangesspringing spirally from around the same, however it be produced, and hasits new and useful features summarizedin the claims which follow thisspecification.

The-chief object of myinvent io n is to contrive a light butst-iff,strong, and durable twist-drill or auger, and such a one as by its addto its; even otherwise unusually great strength of form, other objectsof my present invention being to so distribute the mass of the drillthat corresponding members thereof may bQOf. equal cross-section atsimilar ":parts, and thereby uponthe preferred forgtingmode ofmanufacture better assure the hom ogen'eity'and strength of the drill,it bei g, however, here parenthetically noted thatof the many modes ofmanufacture possible for myimprovcd drill (whether by machinery orotherwise) themethod of producing said drill by a forging process isalso, so far as Iam aware, of my invention and, forms the subject-matterof another application for a UnitedSta-tes patent by inc, eitherherewith concurrently or forthwith intended to be filed in the PatentOffice,and that-the same, therefore, so far as it is herein alluded to,is but incidental to the most apt description which 1 am capable ofmaking of my present inven-' tion, the twist-drill, and not by way of adedication of its mode of manufacture by a forging process to thepublic.

Other of my objects are preferably :to design, contrive, and form atwist or fluted -drill continuous from end to end; also, to so l spaceand form the backs of the lands which intervene between the flutes ofsaid drill that the same may offer without detriment to the drillsself-acting chip-relieving capacity a suitable-bearing for a chuck orother driver engagement; to make the drill, if need be,

double-ended and without sacrifice of mass andsuch efieetivedistribution of the parts as may serve to keep the drill stiff andreliable;

to so fashion the lands of the drill that they by means of merging andcombining them with a central'core or stiffener, and to givethe flangessuch numberfand pitch (rapidity of twist) as shall serve for the propersupport of their edges, and also insure the prompt removal of chips fromtheir cuttingfaces when at work, and preferably, also, to give suchtapering form to the bodies of these lands when viewed in cross-sectionas may serve the better to assist their manufacture between rolls in apreliminary stage of the preferred'forging process aforesaid, togetherwith such preferred formof the central core and other parts as will bebest'understood by reference to the followingdetailed description.

Reference now being had to the accompanying drawings, forming part ofthis specification, in which similar letters of reference indicatecorresponding parts throughout the several figures, they will be foundto illustrate my said improvement intwist-drills as follows, to wit: V

Figure 1 is a side elevation, which shows the point and the portionofthe shank of one of my improv'ed twist-drills in its preferred form.similar drill having a modified form of edge. Fig. '3 is a general sideview of my improved drill in its preferred form, with both ends pointedand edged, the point upon the righthand extremity of-thc drill being,however, represented as sharpened without having the cutting-edgescarried to the extreme center of-thc drill, as the edges upon theleft-hand point are-represented as being. Fig. 4 is a Fig. 2 is asimilar side elevation of a v cross-section upon a slightly-larger scaleof the drill shown in Fig. 3, the plane upon which it is taken beingindicated by the broken line at 00. Fig. 5 is an end View of thepreferred form of cutting-point, or that shown upon the left-hand end ofthe drill represented in Fig. 3. Fig. 6 is a cross-section through thebody of a modified form of the drill. Fig. 7 is a side viewcorresponding to Fig. 3 of a further modification, wherein there arethree flanges springing from the common central core instead of four, asare shown in all the preceding figures. Fig. 8 is a crosssection, alsoupon a slightly-largerscale, of the drill shown in Fig. 7 bya planepassed upon the line yy of said figure; and Fig. 9 is a side elevationwhich showsthepoint and adjoining portion of .the shank ofthe devicewhen specially cont-rivedas anauger. V

In general, as shown in the figures, the drill D consists of two chiefsets of e1ementsone a single central and, as it were, columnar supportor core D ,whi 1e the other comprises three or more lands or flanges d dd d, &c., all arranged in a series merging in and rising from thesaidcommoncore, with and about which core they all, at equal interspace andpreferably nniformpitch, wind in a helix orspire. The .saidlands beingof uniform dimensions, numerous, and lying parallel to the axis of thecore, give a fluted cylindrical outline to the whole. The backs b of thelands also, by approximating, if they do not actually conform to,equivalent areas of a true cylindrical body of equal diameter,preventthe passage of the drill through any orifice other than a circularonethat is, they preventsuch passage unless the drill-shaft thus formedbe rotated in conformity to the pitch of. its screw-like body, when ofcourse it may be possible to pass it through a cross-shapedopeningsubstantially corresponding to the profiles of its flanges andcore when viewed endwise'or viewed asshown in Fig. 5. Such opening androtation in precise conformity to the pitch of the screw are, however,it is almost needless to say, extremely unlikely events to happen withordinary drill feeding and driving, and therefore the drill may insubstance be said to be one which cannot pass through an opening lessthan or in any wise materially varying .from that which it is in pointof fact calculated to bore and fashionviz., a cylindrical or circularaperture. \Vhile I prefer the pitch of the lands to be uniform and theirnumber to be four, with an equal spacing of nine degrees from center tocenter, and the cross-section of the drills core, as shown by dottedlines i in Fig. 4, to be a substantially octagonal figure,the alternatesides of which merge into or are integral with the base of one of thedrills flanges, as will be readily seen from reference to that figure, Ido not wholly limit my improved drills bod yor shaf t to that preciseform or number of flanges, though I much prefer it when so fashioned;and for the sake of further illustration I have therefore shown advancc.

the modifications, Figs. 6, 7, and S, in the former of which, Fig. (3,there is a drill of strictly cruciform cross-section-that is to say, onethe four flanges of which do not taper as they pass outward from theircommon supporting-core, into which core they merge in this case by covesor circular arcs of small radius for the sake of strength, although ofcourse they may, as indicated by dotted lines 1), meet the same alongsharp rcentrant flute-angles-say of ninety degrees each.

In Fig. 8 a drill of my improved sort is shown reduced to one with asubstantially cylindrical core having three flanges (Z d (1, spaced atone hundred and twenty degrees to each other upon any common plane ofcrosssection, thereby sacrificing certain of the more meritoriousfeatures of the preferred straight or St. Andrews cross sort shown inFigs. 1, 2, 3, 4, 5, and ii, for it is evident upon inspection of Fig. 8that the cutting-edges of such a drill or any other in which the flangesare not arranged in pairs each member of which is substantiallydiametrically opposite to its mate, 0]; as shown in Figs. -.t, 5, and(i,

cannot actupon what is commonly known as the duplex and mostadvantageous method of cutting with drills and boring tools for keepingthem true to an established line of However, Figs. 7 and 8 illustrate adrill which will be found in practice to 0perate with many advantageousresults, and, in common with Figs. 1, 9, 3, and 5, shows how my.improved boring device, whatever the number of its flanges or theshapeof its core may be, can be advantageously pointed and sharpened formetal-working or as a drill proper.

Iprefcrablyinakethedrillorauger, as above alluded to, from a billet oftool-steel (or such steel as is proper to make an ordinary edged toolfrom) and b'y any suitable forging operation-snch as taking a sullieientheat upon the billet and passing it one or more times through asuitably-formed groove 01' grooves in a nest of rolls, fashioning itinto a straight blank of uniformed-shaped cross-section throughout itslength, and then,and if possible at the same heat, twisting thisstraight blank to a proper pitch and the multiple-thread screwlike formof twisted blank, which is now substantially-clear. 'lhislatteract oftwisting the blank may be done by a good smith with a mere viso andtongs or wrench-hold and give fair results; but I preferably do it bysuch twisting tools and dies as it is not necessary tohcreparticularlydescribc,sincc thosewhich I find give the best resultsare fully described by'me in my application or applications for ICCpatent for the method of making these drills these blanks by planing ormilling out the flutes and so obtaining either a straight orappropriately spiral blank, and, according to its straight of twistedcharacter at this stage, subsequently proceeding in substantially thelike manner as in the preferred forging method. The pitch of thespireis, I find, with a drill of one inch diameter and four flanges, best ifof about two. and one-half inches. However, it may be-more or lesssteep, and, if need be, as is Well understood by twist-drill and angermakers, of gaining or non-uniform pitch. The final stages in all casesconsist of pointing or otherwise dressing the working end or ends of thedrill or auger to an appropriate shape, then hardening, tempering, andedging the same in order to produce the completed article. 9

The pointing for drills preferably is a conical one-say of sixtydegrees-and the sharp-' cning, which of course is done after the drillhas been wrought, hardened, tempered,- and otherwise prepared in aproper manner for the production of drills, is best efiected, as Icontrive it, by grinding upon the flanges extremities proper angles ofrelief and cutting. edges, and f urtherpreferablysupplerneiiting' thelength of the drills several flanges and cutting-edges by carrying theseedges 6 in a prolongation of each curved flange forward to the centcrofthe core, as by means of what I may call concoidal recesses 0, groundinto the conedpoint of the core D. This will be easily understood byreferring to Figs. land, 5, where the mode of sharpening is the properone for boring into iron or st eel,and where the core of the drillis-shown by such recesses c, fashioned in the manner of a rosedrilla Bythis means the cutting-edges are made to seek and converge in a commoncenter, which of course materially facilitates the case with whichthed'rill may be fed. However, referring to the right-hand extremitiesof Figs. 3 and -7, the drillwill be seen, in both the three and fourflange varieties, to be sharpened in such way as to have the edges andfaces of relief terminating short of the central core, which is here,save only for the quasi cutting action of the somewhat pyram-' idalarrangement of the point of the core, necessary to force through thework without the best cutting action, in which respect the drillmorenearl y corresponds to the action of ordinary drills than it doeswhen fashioned with the preferred rose-sharpening aforesaid. In Fig. 2the rear walls of the flanges are not ground away with relief-faces, butthe front flanges are truncated by grinding them transverse to thegeneral mass of each particular flange, thus giving the requisite obtusesharpening proper for boring into brass and similar material. The core Din this case is also dressed awayin the region of the point to a cylindro-conical or rifle-bullet-like shape, thus giving a chance to grind thecutting edge of each flange to approximatelyits point of commonintersection with the others.

ginal guide-lips in'the manner of ordinary A striking'advantage flowingfrom the uniformity of my improved drill or augers mass, asaptlyjllustrated by the typical cross-section shown-in Fig. 4, residesin the fact that thereby the hardening and tempering pro.-

cesses act uniformly and equally throughout 1 I the whole body of thedrill, and if broken awayv at its edges'it may be quickly repaired by ameregrinding. Y

For an auger an appropriate form of pointing is shown in Fig. 9, wherethe blank is all in a common plane, The edges may also,

as indicated by dotted lines at K K, have maraugers, but with thepreferred four-flange sort. This is,I find, an almost unnecessaryaddition.

what I desire to claim and secure by Letters Patent of the United Statesisc i 1. As a new article of manufacture, a twistnavmgnow fullydescribed my invention,

drill consisting of a central core and fashionedv integral therewith andrising therefrom at substantially equal interspace three or more flangesof similar width, the whole spirally twisted and adapted to be pointedand sharpened substantially as described. 1

2. As a newarticle of manufacture, a twistdrill consisting of a centralcore and three or more helieally-wound flanges rising integral therefromand continuously along the same from end to end, substantially asdescribed.

3. As a new article of manufacture, a drill consisting of asingle forgedbody comprising a central core of substantially octagonal crosssection,as described, and rising therefrom and merging therewith upon alternatefaces of said octagon similar and outwardly-tapering flanges, the wholebeing helieally twisted and adapted to be pointed and sharpened at oneor both ends, substantially as described. 4. As a new article ofmanufacture, a drill consisting of a single forged bodycomprising' acentral core of substantially octagonal crosssection, as described, andrising therefrom and merging therewith upon alternate faces I of saidoctagon similar and outwardly-tapering flanges, the whole beinghelieally twisted, pointed, and sharpened,-the latter by fashioningsuitable cutting-edges and relief-faces .upon the ends of said flangeswhen pointed,

and also by carrying the same to a common center by means'of recessingor rose-pointing the said core, substantially as described. GEO. II.SELLERS.

Witnesses:

LEWIS R. DICK, II. W. HA E POWELL

